manager: Reduce noise from git commands

techtree-manager/src/render.rs

@@ -34,6 +34,8 @@ pub async fn render_and_publish(
         .arg("-C")
         .arg(&render_repo)
         .arg("init")
+        .arg("--initial-branch=render")
+        .arg("--quiet")
         .success()
         .context("Failed to initialize render repository")?;
 
@@ -88,6 +90,7 @@ pub async fn render_and_publish(
         .arg(&render_repo)
         .arg("push")
         .arg("--force")
+        .arg("--quiet")
         .arg(repo_auth_url.to_string())
         .arg("HEAD:refs/heads/render")
         .status()